1. Field of the Invention This invention relates to a cutting tool for trimming the flash from blow-molded plastic parts.
2. Description of the Prior Art
Removing flash from blow-molded plastic parts is a well known problem in the industry, and various methods have been developed to achieve removal of flash from blow-molded parts. The most common method of flash removal from blow-molded plastic parts is manual deflashing. This two stage process begins with a worker using a knife and/or a hammer to cut away the bulk of the flash known as "rough deflashing", followed by the worker using a scrapper to remove the remaining smaller pieces of flash and smooth the edges of the part known as "finish deflashing". This process is extremely labor intensive, and therefore expensive. Additionally, the use of sharp knives and scrappers by workers is hazardous to the workers themselves, and the associated injuries are costly to the manufacturer.
Another method incorporates the use of high-tech hardware and software to locate the parting line of the flash and then uses a tracking algorithm to guide a cutting tool along the parting line. These tracking algorithms are slow to react to changes in the part geometry, however, causing the cycle time for deflashing the part to be very long. Additionally, the complexity of the system and the inaccuracy of the sensors make a clean, accurate edge difficult to attain.
Finally, a third method of deflashing uses a cutting tool with a roller or bearing mounted to the tool which will ride along the part surface and guide the cutting of the tool. This set-up is difficult to control, however, as the roller or bearing rides along the part at some distance from the point the flash is being cut. This type of point contact between the tool and the part encourages the tool to bounce or jump at sharp edges or changes in part geometry. Also, since support is provided by a point contact between the tool and the part, there is no rotational support to insure that the tool is oriented accurately as it travels around the edge of the part.